tbuckley/cabot-search huggingface dataset:
P12.06.A Relationship between ascorbate and DNA methylation markers in clinical glioma tumours
Authors: R L I Crake, E R Burgess, G A R Wiggins, N J Magon, A B Das, M C M Vissers, H R Morrin, J A Royds, T L Slatter, B A Robinson, E Phillips, G U Dachs
Journal: Neuro-Oncology (2022)

Abstract Background Members of the 2-oxoglutarate-dependent dioxygenase (OGDD) enzyme family play an important role in gliomas as they regulate epigenetic modifications and response to hypoxia. The OGDDs require 2-OG and O2 as substrates, and ferrous iron and ascorbate as cofactors. Both hypoxia and aberrant DNA methylation are prognostic indicators for gliomas. The ten-eleven translocase (TET) DNA demethylases are OGDDs that convert 5-methyl cytosine (5mC) to 5-hydroxymethylcytosine (5hmC), with 5hmC levels related to better prognosis. Despite this, there is limited data on the OGDD enzymes and their substrates/cofactors in glioma tissues. Our previous study showed an association between ascorbate content and markers of the hypoxic response in glioblastoma tissue. Here we determine whether there is an association between ascorbate and DNA methylation in glioma. In addition, we assess whether methylation of the methylguanine-DNA methyltransferase (DNA repair enzyme MGMT) promoter is associated with ascorbate content. Materials and methods Frozen clinical glioma samples from 37 patients (n=11 WHO grade I-III, n=26 glioblastoma) were obtained from the Cancer Society Tissue Bank (Ethics approval H19/163). Isocitrate dehydrogenase 1 (IDH1) mutation status was determined by sequencing. Samples were processed on dry ice in liquid nitrogen and analysed for ascorbate (high-performance liquid chromatography), global DNA methylation (mass spectrometry) and MGMT promoter analyses (methylation specific PCR). Results Many grade I-III tumours were IDH1 R132H mutant (6/11), and most glioblastomas were not (2/26). Glioblastoma had significantly lower ascorbate content than grade I-III tumours (p=0.026). Glioblastoma also had lower global 5hmC levels (p=0.0013). IDH1 R132H tumours tended to have a lower ascorbate content (p=0.09). Ascorbate and 5hmC levels were directly correlated (Spearman r= 0.466, p=0.004). However, cytosine and 5mC showed no association with grade or ascorbate. MGMT promoter methylation status was not associated with global methylation or ascorbate content (p=0.97, p=0.96, respectively). Conclusion Our data suggests that ascorbate supports TET activity in clinical glioma. It also appears that site-specific (promoter) methylation was not affected by ascorbate availability. These findings may have clinical implications, as higher 5hmC levels are associated with improved outcome, whilst continued MGMT suppression suggests chemotherapy responsiveness. However, evidence that raising tumour ascorbate leads to increased 5hmC levels, or an associated improvement in survival, requires intervention trials.
P10.02.B The fragile balance between proliferation and neoplasia in neural stem cells: role of DIAPH3 in glioblastoma
Authors: G Chehade, N Ruiz-Reig, C Raftopoulos, N Tajeddine, F Tissir
Journal: Neuro-Oncology (2022)

Abstract Background DIAPH3 belongs to the formin family of proteins that are master regulators of the cell cytoskeleton. DIAPH3 plays a key role in cytokinesis as well karyokinesis. Hence, in the mouse brain, DIAPH3-deficient neural stem cells exhibit abnormal cell division leading to aneuploidy and apoptosis of cells progeny. Given the importance of aneuploidy in cancer development and progression, we asked whether DIAPH3 loss could be involved in the genesis and the aggressiveness of brain tumors. Material and Methods We co-inactivated Diaph3 and Trp53 genes in the mouse cerebral cortex using the Emx1-Cre mouse line (Diaph3/Trp53 dcKO). As a control, we inactivated only Trp53 gene using the same Cre mouse line (Trp53 cKO). Mouse survival was analyzed, and tumors were collected for histological analysis as well as molecular characterization. Additionally, we measured DIAPH3 expression in human glioblastoma samples and studied its impact on patient overall survival. Results Diaph3/Trp53 dcKO develop brain tumors earlier compared to Trp53 cKO resulting in a decrease of mouse survival. Hematoxylin-eosin staining, as well as GFAP, OLIG2 and KI67 immunostainings strongly suggest that the tumors are glioblastomas. Quantitative reverse transcription PCR performed on biopsies from 73 patients uncover variable DIAPH3 expression levels in glioblastoma samples. Interestingly, multivariate Cox proportional-hazards analysis shows that low DIAPH3 expression predicts a worse overall survival, independently from other known prognosis factors. Conclusion On one hand, our study shows that DIAPH3 loss favors glioblastoma development in mouse, strongly suggesting a tumor-suppressor role for DIAPH3. On the other hand, the clinical study shows that DIAPH3 low expression has a negative impact on patient overall survival indicating that DIAPH3 loss may favor resistance to chemotherapy and/or radiotherapy.
P12.05.B Impact of GAP-43 and actin expression on the outcome and overall survival in diffuse and anaplastic gliomas
Authors: A Krigers, M Demetz, P Moser, J Kerschbaumer, K R Brawanski, C Thomé, C F Freyschlag
Journal: Neuro-Oncology (2022)

Abstract Background Distant intercellular communication in gliomas is based on the expansion of tumor microtubuli (TMs), where actin forms cytoskeleton and GAP-43 mediates the axonal conus growth. We aimed to investigate the impact of GAP-43 and actin expression on overall survival (OS) as well as crucial epidemiologic, radiological and neuropathological prognostic factors. Material and Methods FFPE tissue of adult patients with diffuse and anaplastic gliomas, who underwent first surgery in our center between 2010 and 2019, were selected. GAP-43 and actin expression was analyzed using immunohistochemistry and semi-quantitatively ranked. Clinical, neuropathological as well as follow-up-data were gained from the institutional neuro-oncological database. Results 118 patients with a median age of 46 years (IqR: 35 - 57) were evaluated. 48 (41%) presented with a diffuse glioma and 70 (59%) revealed anaplasia. 96 (82%) cases presented with intermediate or strong GAP-43 expression and 78 (67%) with no or light actin expression. Tumors with higher expression of GAP-43 (p=0.024, HR=1.71/rank) and actin (p&amp;lt;0.001, HR=2.28/rank) showed significantly reduced OS. IDH wildtype glioma demonstrated significantly more expression of both proteins: GAP-43 (p=0.009) and actin (p&amp;lt;0.001). The same was confirmed for anaplasia (GAP-43 p=0.028, actin p=0.029), higher proliferation rate (GAP-43 p=0.016, actin p=0.038), contrast-enhancement in MRI (GAP-43 p=0.023, actin p=0.037) and age (GAP-43 p=0.004, actin p&amp;lt;0.001). Conclusion The intercellular distant communication network in diffuse and anaplastic gliomas formed by actin and GAP-43 is associated with a negative impact on overall survival and unfavorable prognostic features.
P11.31.B Pseudotumor Cerebri - a rare paraneoplastic manifestation
Authors: R Ivan, L C Nistor, C G Lipan, R M Mezei, C A Sirbu
Journal: Neuro-Oncology (2022)

Abstract Background Pseudotumor Cerebri (PC) is defined by an elevated intracranial pressure of unidentified cause, associated with normal cerebrospinal fluid (CSF) composition and no cause for hypertension on the neuroimaging evaluations. The symptoms described in association are headache, papilledema, changes in vision, and sometimes tinnitus. Its pathophysiology is far from being elucidated and the mechanisms proposed are multiple. There are some cases described in the literature in which PC is the first manifestation of a systemic neoplasm, most probably due to an abnormal response of the immune system to cancerous growth. We aim to emphasize a possible connection between adenocarcinoma of the lung and PC as the first paraneoplastic manifestation. Material and Methods We present the case of a 59-year-old patient, female, non-obese, who presented to the hospital for severe headache, blurred vision, tinnitus, and paresthesia on both her upper limbs. On the first evaluation, the usual blood tests showed an increased creatinine level, and the subsequent abdominal echography and CT scan revealed bilateral ureter hydronephrosis, without an obvious obstacle, for which nephrostomies were implanted. On the ophthalmological evaluation bilateral papillary edema was described, although the cerebral CT with angiography and MRI showed no pathological modifications. A lumbar puncture with manometry was performed, that showed a CSF pressure of approximately 500 mmH2O. Results Following the clinical, imagistic, and biological manifestations, the diagnosis of PC was established. The decision to start the corticotherapy was made, followed by the addition of acetazolamide. Although the treatment tented was not efficient, the neurosurgery team decided that she is not a suitable candidate for a CSF shunting procedure and the ophthalmologist advised against an optic nerve sheath fenestration. The evolution was unfavorable, with the persistence of the symptoms. She underwent extensive investigations, the second cerebral MRI showing a slight dilation of the ventricles. On the thoracic-abdominal-pelvic CT, a pulmonary nodule with a malignant aspect was described, the histopathological results pleading for adenocarcinoma. The decision to excise the lesion was made, but after the surgery, the patient developed a cardiorespiratory arrest, without response to resuscitation. Conclusion Although there is scarce evidence of PC as a paraneoplastic syndrome, the evolution and investigations results support the possibility of a causal relationship. This is, to our knowledge, the second case of adenocarcinoma of the lung that primarily presents with PC. Further studies must be conducted to understand the underlying pathophysiology of this condition and to develop new treatment possibilities.
P07.03.A Advances in Robotic Navigated Laser Craniotomy. An in-vivo non-recovery animal study
Authors: F Winter, D Beer, M Morawska, C Dorfer, K Roessler
Journal: Neuro-Oncology (2022)

Abstract Background We previously described a new frameless stereotactic intervention using robotic guided laser beam for depth electrode placement. This study tested the feasibility of a new cutting strategy for angulated precision bone channels as well as improved cut-through detection using optical coherence tomography (OCT) and a new generation of co-axial live video feed. Material and Methods Preoperative CT scans were performed to plan trajectories for bone channels angulated 45, 60, and 90° relative to the surface. The animals were prepared under general anesthesia by a trained veterinarian conforming European requirements and Good Laboratory Practice regulations. A new cutting strategy was implemented consisting of two circular paths and three different ablation phases. After cut-through detection bolts and depth electrodes were inserted. Before termination ad-hoc planned laser craniotomies were performed to evaluate possible cortex damage. Results 70 robotic guided laser beam precision bone channels were cut in four pig specimens. Bolts and depth electrodes were implanted solely guided by the trajectory given by the laser precision channels. The new cutting strategy showed no irregularities for either cylindrical (n=38, 45°=10, 60°14, 90°=14) or anti-conical (n=33, 45°=11, 60°=13, 90°=9) bone channels. Angulation and hole diameter showed no significant difference between cylindrical and anti-conical cutting strategies. The updated co-axial camera live video feed in addition to OCT reliably detected cut-through in 80% of cases. Insertion of bolts with firm fit was achieved in 94% of bone channels. All four anesthesia protocols showed no irregularities. No unintended damage to the cortex was detected after laser guided craniotomy. Conclusion The new cutting strategy showed promising results in 70 precision bone channels for angulated cylindrical and anti-conical channels in a large in-vivo non-recovery animal study. OCT signal and a new co-axial camera proved its feasibility for cut-through detection. Robotic guided laser beam techniques proved its feasibility for the placement of depth electrodes and might be a suitable option to optimize the burr hole for biopsies.
P10.17.B Androgen receptor signalling has independent prognostic value and is associated with resistance to temozolomide and tumour growth in glioblastoma
Authors: C Birzu, J Boussier, L Belin, T Da Costa Pereira, E Quissac, M Zerara, N Lemaire, K Mokhtari, M Verreault, A Idbaih
Journal: Neuro-Oncology (2022)

Abstract Background The spectrum of sex differences in glioblastoma (GBM) is a rising topic. GBM is more frequent (sex ratio M:F=1.6) and seem to have worse prognosis in males (M) compared to females. Androgen receptor (AR) is expressed in GBM but its role in GBM biology and clinics is not yet fully understood. Material and Methods We have selected from our tumour tissue bank: (i) GBM samples with clinical, pathological and molecular annotations and (ii) GBM-patient derived cell lines -GBM-PDCL- with transcriptomic profiling and available tissue from parental tumours.AR expression was investigated using multiplex IHC Opal stained-FFPE sections. Sensitivity of PDCL to hormonotherapy (dihydrotestosterone or enzalutamide EZT) alone or combined with temozolomide (TMZ) was tested using WST1 viability assay. Response to drugs were correlated to AR expression (high: log2 [FPKM] &amp;gt;2 or low: log2 [FPKM] &amp;lt;2). PDCLs dihydrotestosterone secretion was examined by ELISA in both supernatants and cell lysates. Results In our cohort of 1188 IDH muted GBM patients, the median follow-up was 27.7 (25.8-31.3). The sex ratio M:F was 1.68 and the median age at diagnosis was 57 years [18-69]. Compared to males, females have better prognosis with a median overall survival of 26.1 months vs 20.8 months (p&amp;lt;0.0001). In multivariate analysis, male gender was an independent prognostic factor with a HR of 1.43 CI95%(1.21-1.69) (p&amp;lt;0.0001) adjusted on age, MGMT status and Karnofsky indice . Although interaction between age and sex was not significant (p = 0.854), HR of gender varied through age category 1.53 CI95%( 1.01-2.33 ), 1.51 CI95%( 0.888-2.55 ) and 1.38 CI95%( 0.857-2.21) for males &amp;lt;45 years, between 46-55 years and &amp;gt; 55 years respectively. In GBM tumours, AR staining was positive in 5- 30% tumour cells. After 72h exposure to 10nM dihydrotestosterone, ARhigh GBM-PDCLs exhibit AR nuclear translocation and c-myc expression upregulation, suggesting functional activation of the receptor. AR pharmacological blockade increased temozolomide sensitivity in ARhigh GBM-PDCLs regardless of the patient’s sex. Moreover, ARhigh PDCLs secreted DHT, suggesting autocrine and paracrine AR stimulation in tumour microenvironment. Conclusion Our study highlights the independent prognostic significance of sex in GBM patients, where males exhibit a worse prognosis. In GBM-PDCL, we show that androgen receptor is (i) functional in vitro and (ii) associated with resistance to temozolomide. Further studies are needed to investigate the role of AR in tumour tissue microenvironment.
P07.06.B The Impact of Using Intraoperative Ultrasound on Surgical Resection of High-Grade Glioma: A Systematic Review and Meta-Analysis
Authors: G Solomou, A Christou, C S Gillespie, O Khouli, P Plaha
Journal: Neuro-Oncology (2022)

Abstract Background Despite operative and adjuvant therapies, high-grade glioma (HGG) remains incurable, with the extent of surgical resection being one of the modalities that can improve patient survival. Enabling maximal safe and minimising post-operative neurological morbidity is a key aim of surgical resection. Numerous intraoperative surgical adjuncts are used at surgery and intraoperative ultrasound (IoUS), is one such adjunct. IoUS is a cost-effective, easy to use, repeatable surgical adjunct, safe for the patient and potentially available in all centres. Although it’s commonly used, no up to date systematic review exists collating and quantifying the level of evidence, delineating its impact on the extent of surgical resection. Material and Methods A systematic review was conducted according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. The study was registered with the PROSPERO database (CRD42022300034). Keywords across Medline/PubMed and Embase between 1996 and November 2021 were used. We included articles with adult supratentorial, histopathologically confirmed HGG patients aimed for resection, evaluating the correlation of IoUS use and gross-total resection (GTR). Meta-analyses were conducted according to the statistical heterogeneity between the studies using the Open Meta Analyst software. Results 2942 articles were identified of which 16 were qualitative assessed and 10 used for quantitative meta-analysis. In qualitative assessment, a mean 4.63/8 Newcastle-Ottawa-Scale score was found for studies with no cohorts (no use of IoUS) and a mean score of 6/9, for studies including exposed versus non-exposed cohorts. The RCT was of moderate quality according to the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) tool. A pooled analysis across 10 studies of HGG aimed for resection with the use of IoUS, led to GTR achieved in 168/365 cases, resulting in an overall GTR rate of 51.1% (95% CI, 33.9%-68.3%, p&amp;lt;0.001), with great heterogeneity across studies (93.02% p&amp;lt;0.001). In a subgroup meta-analysis of 3 studies of HGG aimed for complete resection only, GTR was achieved in 43/62 cases, yielding a 72.7% GTR rate (95% CI 41.6%-100%, p&amp;lt;0.001) with significant heterogeneity across studies (I2 92.1%, p&amp;lt;0.001). In 4 case-controlled studies, a total of 43.6% (48/110) GTR rate was achieved when IoUS was used versus 24.7% (65/263) when IoUS was not used, resulting in an odds ratio = 2.009 (95% CI 1.157-3.490, p &amp;lt;0.001) for achieving GTR. Conclusion The meta-analysis showed a high GTR rate (72.7%) when HGG were aimed for complete resection and a two-fold probability of achieving GTR when IoUS is used than not used.
P11.01.B Lower-extremity deep vein thrombosis and bleeding complications in primary brain tumor patients: A prospective study
Authors: V Muster, R B Raggam, T Urbanic-Purkart, F Posch, K Gütl, J Rabensteiner, F Prüller, G von Campe, M Rief, M Brodmann, T Gary
Journal: Neuro-Oncology (2022)

Abstract Background Primary brain tumor patients have a high risk of venous thromboembolism (VTE). Bleeding risk with prophylactic and therapeutic anticoagulation is an important concern in these patients, and data on the management of asymptomatic VTE events in this population are lacking. The aim of this prospective study is to investigate risk and risk factors for asymptomatic lower-extremity deep-vein thrombosis (LE-DVT) in patients with primary brain tumors, and to estimate the rate of bleeding complications on full, prophylactic or no anticoagulation. Material and Methods We included consecutive patients with primary brain tumours undergoing surgery. Screening for asymptomatic LE-DVT by compression ultrasound (CUS) was performed pre-operatively and postoperatively within 2 months after surgery. Telephone follow-up was done 6 and 12 months after surgery. The protocol pre-specified therapeutic doses of low-molecular-weight heparin (LMWH) in case of detection of an asymptomatic LE-DVT. Results Fifty patients were included (female: 34%, median age 58 years, WHO grade IV tumors: 78%, prophylactic-dose LMWH at baseline: 12%). During a median observation period of 9.1 months, LE-DVT was detected in 9 patients (18%). LE-DVTs included two asymptomatic events (4%) at pre-operative screening, five asymptomatic events (10%) at postoperative screening, and two symptomatic events (4%, both 4-level LE-DVT) at telephone follow-up. This corresponded to a 12-month cumulative incidence of LE-DVT of 14.9% (95%CI: 6.4-26.6). At postoperative screening, n=10 patients were on prophylactic-dose LMWH, and one of these patients had an LE-DVT event detected by screening. The two patients with symptomatic LE-DVT were not on thromboprophylaxis at the time of event. Among a variety of investigated potential risk factors, only higher age (Odds Ratio (OR) per 5 years increase=1.46, 95%CI: 1.01-2.13, p=0.05), higher neurologic assessment in neuro-oncology (NANO) scale (OR per 1 point increase=1.59, 1.00-2.54, p=0.05), higher serum Galectin-3 levels (OR per 1ng/ml increase=1.20, 1.01-1.42, p=0.041) but not D-Dimer (OR per 1mg/L increase=1.89, 0.75-4.77, p=0.178) emerged as significant predictors of any LE-DVT. Six patients (12%) developed bleeding events, including n=3 operative intracranial bleedings without LMWH, n=1 spontaneous ventricular hemorrhage without LMWH, n=1 minor subcutaneous bleeding without LMWH, and 1 intracerebral hematoma during therapeutic-dose LMWH initiated for asymptomatic distal LE-DVT. Conclusion In our study we detected a high-frequency of asymptomatic LE-DVT in patients with primary brain tumours. Conversely, symptomatic LE-DVT risk was low, which may be related to prior screening. Patients with primary brain tumors appear to have LE-DVT risk factors specific to this entity. Prophylactic-dose LMWH did not show any adverse safety signals regarding bleeding.
P05.05.B A new IDH-wildtype glioma subtype characterized by highly diffuse growth pattern, distinct epigenetic profile and relatively favorable prognosis
Authors: A Münch, D Teichmann, P Kuzman, D Spille, E Perez, S May, W Mueller, T Kombos, S Nazari-Dehkordi, J Onken, P Vajkoczy, G Ntoulias, W Paulus, F Heppner, A Koch, D Capper, D Kaul, C Thomas, L Schweizer
Journal: Neuro-Oncology (2022)

Abstract Background DNA methylation profiling has emerges as a powerful approach to CNS tumor classification and the discovery of novel, molecularly distinct entities. With the release of the 12.5 version of the Heidelberg Brain Tumor Classifier, some unclassifiable cases can be assigned to novel methylation classes. We retrospectively reviewed our databases and identified 16 previously unclassifiable cases, all of which belong to the provisional methylation class “adult-type diffuse high-grade glioma, IDH-wildtype, subtype F (HGG_F)”. Material and Methods We clinically, radiologically and morphologically characterized 16 HGG_F cases and compared them to 347 glioblastomas. We additionally analyzed copy-number alterations and performed DNA exome sequencing. Results Median age at diagnosis of the 12 males and 4 females was 65 years. Upon initial diagnostic workup, specimens were classified as CNS tissue with reactive changes (n=3) or suspicious for the infiltration zone of a diffuse glioma (n = 13). None of the cases demonstrated endothelial proliferation or necrosis and 10/16 tumors had flat copy number profiles. Radiological characteristics were reminiscent of gliomatosis cerebri in eight cases and 9/9 cases had normal FET-PET scans. Whole-exome sequencing revealed genetic alterations frequently found in IDH-wildtype glioblastomas, including TERT promoter mutations in 11/14 (78.6%) and PIK3 mutations (10/14, 71.4%). Outcome was significantly better compared to TCGA IDH-wildtype glioblastomas with a median progression-free survival of 58 months and overall survival of 73 months (both p&amp;lt;0.001). Conclusion We provide evidence that TERT promoter mutations in diffusely infiltrating gliomas without further morphological or molecular signs of high-grade glioma should be interpreted in the context of the clinico-radiological presentation as well as epigenetic prolife and may not be suitable as standalone diagnostic marker for glioblastoma, IDH wildtype.